1. Field of the Invention
The present invention is directed to a dispenser-applicator adapted for applying spreadable substances to solid surfaces. More particularly, the present invention is directed to a dispenser-applicator for applying pre-measured convenient amounts of spreadable substances, such as liquids, gels, lotions, and readily melting solids, to surfaces.
2. Brief Description of the Prior Art
Spreading various substances, such as lotions, ointments, gels, lubricants, skin medications, as well as liquidy or pasty foodstuffs, on solid surfaces, and frequently on irregular surfaces, is very old in the art. Spreading of lotions or semi-solid creamy or pasty external medications on various parts of the human body, and the application of butter to corn-on-the-cob may be mentioned in this connection as specific examples where a convenient, preferably pre-measured relatively small portion of a spreadable substance is to be applied preferably evenly to an irregular surface.
In view of the nature and ubiquitousness of the problem in human experience, it is perhaps not surprising that a very large number of dispenser devices adapted for various types of specific applications have been described in the prior art.
U.S. Pat. No. 3,334,374, for example, discloses an applicator pad having a liquid impermeable back wall, and a liquid permeable front wall with a pocket or storage space being formed between the two. The front wall may be a perforated sheet or an absorbent material. A liquid agent to be applied with the applicator pad is kept in rupturable capsules within the pocket When the applicator pad is pressed sufficiently firmly against a surface, the capsules are ruptured, and the liquid is applied to the surface through the front wall.
U.S. Pat. No. 2,961,677 discloses an applicator for a single dose of shoe polish or the like, having a porous pad. A pocket for liquid or liquidy paste is formed from a pierceable plastic material on one side of the porous pad in such a manner that during normal storage the liquid is isolated from the pad. A gripping member or handle is mounted to the plastic material leaving the front surface of the pad available for contact with a surface upon which the liquid is to be spread. When it is desired to use liquid or liquidy paste, the plastic wall separating the porous pad from the liquid is pierced with a needle and the liquid is slowly squeezed out to the surface through the pores of the pad.
U.S. Pat. No. 4,291,697 discloses a cleaning or applicator device which has a frangible capsule of liquid embedded in a relatively flat sponge member. The sponge embedding the capsule is mounted to an elongated handle. When it is desired to apply the liquid contents of the capsule with the sponge, pressure is exerted on the sponge to break the embedded capsule, and the liquid is allowed to soak into the sponge.
U.S. Pat. No. 4,430,013 describes an applicator for a liquid substance having a foam pad, and a liquid reservoir attached to one side of the pad. The liquid reservoir, although made of relatively rigid plastic, has a weakened portion, caused, for example, by a slit or scoring, so that pressure exerted in a given direction, or bending of the rigid plastic, breaks the weakened portion. When the weakened portion breaks, the liquid spills into the foam pad and is applied therefrom to a desired surface.
An applicator device somewhat similar in construction and operation to the just-described patented device is disclosed in U.S. Pat. No. 4,493,574. The "dispenser package" of the U.S. Pat. No. 4,493,574 has a flexible pouch adhered to a relatively stiff material. The package may be opened along a fault line or cut pattern in the stiff material by bending or flexing the stiff material in a V-shaped pattern. The dispenser package of this patent serves reasonably well for storing and dispensing single doses of liquid substances or liquidy pastes especially in situations where even spreading on a surface is not important. For example, the dispenser package of U.S. Pat. No. 4,493,574 serves reasonably well for dispensing certain liquidy or liquidy-pasty food condiments, such as mustard, ketchup, or honey.
U.S Pat. No. 4,493,574 also describes an embodiment of a dispenser package which contains a sponge to catch the liquidy substance when the overlying stiff material is broken along a fault line. This embodiment is said to be suitable for applying the liquidy substance to a surface in a "swab" type application. In reality, however, this device, due to its particular configuration and due to the presence of the relatively sharp edges of the broken stiff material, is not well suited for evenly spreading a liquid on any surface. This device is particularly ill suited for an application where the surface (such as a wounded skin) is sensitive to touch, pressure, or damage by the broken stiff material. The device of U.S. Pat. No. 4,493,574 is also not well suited for dispensing solid or semi-solid substances, and particularly not suited for relatively evenly dispensing and spreading solid or semi-solid substances on a solid surface, and even less so on an irregular surface.
Generally speaking, those dispensers and applicators of the prior art which aim to dispense a convenient single portion or dose of a spreadable material (for example, the applicator packages of U.S. Pat. Nos. 4,430,013 and 4,493,574) tend either to be unable to dispense all of their contents, or to dispense the contents in a poorly controlled manner and therefore waste the spreadable material. This is clearly undesirable.
For more background and detailed information on the prior art to the present invention, further reference is made to the following U.S. Pat. Nos. 2,829,393; 3,014,579, 3,214,781; 3,768,916; 3,818,911; 3,826,259; 3,896,808; 4,148,318; 4,173,978; 4,183,684; 4,240,760; 4,515,703, and to Canadian Patent No. 945918.
In light of the foregoing, it is apparent that the relatively large number of patent disclosures and devices developed in the prior art for dispensing liquid and pasty materials as well as for applying them on various surfaces, have not solved all problems related to this art. There is still further serious need in the art for dispensers and applicators well adapted for dispensing and applying convenient amounts, preferably single doses, in a well-controlled manner, not of just liquids but also of gels, semi-solids, and certain solids (such as butter), on solid surfaces. The present invention provides such applicator and dispenser devices.